Sealing Assembly Of A Ball Joint And Ball Joint

ABSTRACT

A sealing assembly of a ball joint, in particular for a vehicle, comprises a retaining ring which includes a ring axis and a radial ring flange having a flange upper side and an opposed flange lower side, and a sealing element which rests against the flange upper side and against the flange lower side and is exclusively connected to the retaining ring with an interlocking fit, the interlocking fit being configured such that the retaining ring and the sealing element are fixed to each other free of play in the axial and in the radial direction, and the flange upper side having an exposed contact surface for a sealing bellows.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. Ser. No. 12,922,964 filed Oct.11, 2010, the disclosures of which are incorporated herein by referencein entirety, which was a national stage of International Application No.PCT/EP2009/001998 filed Mar. 18, 2009, the disclosures of which areincorporated herein by reference in entirety, and which claimed priorityto German Patent Application No. 10 2008 014 695.1 filed Mar. 18, 2008,the disclosures of which are incorporated herein by reference inentirety.

BACKGROUND OF THE INVENTION

The invention relates to a sealing assembly of a ball joint, inparticular for a vehicle, and to a ball joint having such a sealingassembly.

Ball joints for motor vehicles are generally known and are usuallyprotected against the penetration of dirt and moisture and against theescape of joint grease by means of a sealing bellows or a sealing cup.In today's usual embodiments, the sealing bellows is sealingly attachedon both sides, i.e. to the joint housing and to the ball stud so thatthe joint is sealed and a reliable joint function is ensured.

However, in the conventional attachment variants, a rusting of the ballstud and a malfunction of the sealing can occur due to a capillaryaction via the components attached adjacent thereto.

A possible remedy to this problem is proposed in DE 10 2004 063 013 A1,and corresponding U.S. Patent No. 2010/0025950A1, the disclosures ofboth of which are incorporated by reference herein in entirety, forexample. In this document, a support ring is provided which has a sealmounted to a shaft flange profile with an inter-material bond and whichstatically seals the joint sealing system with respect to the leversocket. The inter-material joint between the seal and the support ringhowever constitutes a complicated and cost-intensive solution.

Document JP 2 199 317 discloses a ball joint having a support ring, inwhich a seal is fastened in a similar manner, the seal and the supportring being bonded to each other. In one embodiment, the sealing elementis pulled around the outer edge of the support ring flange.

BRIEF SUMMARY OF THE INVENTION

The invention is directed to a sealing of a ball joint, which is asreliable, simple and cost-effective as possible.

This is achieved by a sealing assembly of a ball joint according to theinvention, in particular for a vehicle, comprising a retaining ringwhich includes a ring axis and a radial ring flange having a flangeupper side and an opposed flange lower side, and a sealing element whichrests against the flange upper side and against the flange lower sideand is exclusively connected to the retaining ring with an interlockingfit, the interlocking fit being configured such that the retaining ringand the sealing element are fixed to each other free of play in theaxial and in the radial direction, and the flange upper side having anexposed contact surface for a sealing bellows. Fixed in the axialdirection means more precisely that the retaining ring and the sealingelement are fixed to each other free of play in both axial directions.As a result of the exclusive interlocking fit between the sealingelement and the retaining ring, it is possible to do without expensiveadhesives or adhesion promoters. Furthermore, the pure interlocking fitalso simplifies the manufacturing method of the sealing assembly so thatthe material and manufacturing costs are generally reduced.

In other respects, this is also achieved by a sealing assembly of a balljoint, in particular for a vehicle, comprising a retaining ring having aring axis and a radial ring flange, and a sealing element connected tothe retaining ring with an interlocking fit, at least one projectionand/or at least one recess being provided on the ring flange, and theprojection of the ring flange engaging in a recess of the sealingelement, or a projection of the sealing element engaging in the recessof the ring flange, respectively, to realize the interlocking fit. Dueto a simple interlocking fit, a durable, reliable and cost-effectivefastening of the sealing element to the retaining ring is also realizedin this case.

In this alternative solution, the sealing element can selectively alsobe attached to the retaining ring free of play in the axial and in theradial direction by means of the interlocking fit.

Other advantages of this invention will become apparent to those skilledin the art from the following detailed description of the preferredembodiments, when read in light of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a sectional drawing through a ball joint according to theinvention having a sealing assembly according to the invention;

FIG. 2 shows a section through the sealing element of the sealingassembly of the invention according to a first embodiment;

FIG. 3 shows a detail section through the sealing assembly of theinvention according to the first embodiment;

FIG. 4 shows a detail section through the ball joint according to theinvention having a sealing assembly of the invention according to thefirst embodiment;

FIG. 5 shows a section through a retaining ring of the sealing assemblyof the invention according to a second embodiment;

FIG. 6 shows a top view on the retaining ring according to FIG. 5;

FIG. 7 shows a detail section through the ball joint according to theinvention having a sealing assembly of the invention according to thesecond embodiment;

FIG. 8 shows a section through the sealing assembly of the inventionaccording to a third embodiment;

FIG. 9 shows a section through the sealing assembly of the inventionaccording to a fourth embodiment;

FIGS. 10 a and 10 b show sections through a retaining ring and theoverall sealing assembly of the invention according to a fifthembodiment, respectively;

FIG. 11 shows a section through the sealing assembly of the inventionaccording to a sixth embodiment;

FIG. 12 shows a section through the sealing assembly of the inventionaccording to a seventh embodiment;

FIG. 13 shows a section through a retaining ring for the sealingassembly of FIG. 12 before mounting of the sealing element;

FIG. 14 shows a section through a sealing element for the sealingassembly according to FIG. 12;

FIG. 15 shows a section through the sealing assembly of the inventionaccording to an eighth embodiment;

FIG. 16 shows a section through a retaining ring for the sealingassembly according to FIG. 15 before mounting of the sealing element;

FIG. 17 shows a section through a sealing element for the sealingassembly according to FIG. 15;

FIG. 18 shows a section through the sealing assembly of the inventionaccording to a ninth embodiment;

FIG. 19 shows a sectional drawing through a ball joint according to theinvention having a sealing assembly according to the ninth embodiment;

FIG. 20 shows a section detail of the ball joint of FIG. 19; and

FIG. 21 shows the section detail of FIG. 20 in an alternativeconfiguration.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a ball joint 10, in particular for a vehicle, having a ballstud 12 including a ball head 14 and a shank portion 16, a joint housing18 with a bearing shell 19, which can receive the ball head 14, asealing bellows 20 for sealing a transition region between the ball stud12 and the joint housing 18, and a sealing assembly 22. The sealingbellows 20 is fastened, on the one hand, to the joint housing 18 bymeans of clamping rings 24, and, on the other hand, to the shank portion16 of the ball stud 12 by means of the sealing assembly 22. The sealingassembly 22 has a retaining ring 26 and a sealing element 28 connectedto each other with an interlocking fit.

The cross-section of the retaining ring 26 preferably has a L-profile.

The general structure and the functioning of the ball joint 10 arealready generally known from the prior art and are not described in moredetail. The characteristic features of the ball joint 10 according toFIG. 1 are based on the design of the sealing assembly 22 which isdescribed in more detail with reference to the figures below:

FIG. 2 shows a detail section through the sealing element 28 for thesealing assembly 22 according to a first embodiment. An elastomer, inparticular a thermoplastic polyurethane (TPU) elastomer is preferablyused as material for the sealing element; it can however be made of adifferent material having similar properties. In this first embodiment,the sealing element 28 is preferably directly injection-molded with theretaining ring 26 and forms an interlocking fit with the latter (seeFIG. 3). The use of particular adhesion promoters in the injectionmolding compound of the sealing element 28 is not necessary as thesealing element is reliably fastened to the retaining ring 26exclusively by means of the interlocking fit.

The use of a separating agent between the injection molding compound ofthe sealing element and the retaining ring 26 can optionally be providedin order to prevent an adhesive joint between the retaining ring and thesealing element.

FIG. 3 shows a section through the sealing assembly 22 with the sealingbellows 20 mounted.

The retaining ring 26 has a sleeve-shaped portion 30 extendingsubstantially in the axial direction with respect to a ring axis A, thesleeve-shaped portion being also adapted to be conically widened orcontracted. A radial ring flange 32 having a flange upper side 34 and aflange lower side 36 integrally adjoins the sleeve-shaped portion 30 ofthe retaining ring 26.

In the first embodiment according to FIGS. 2 to 4, the sealing element28 engages around a radially outer peripheral edge 54 of the ring flange32 (preferably over the entire peripheral edge 54) so that aninterlocking fit free of play is realized between the retaining ring 26and the sealing element 28 both in the radial and in the axialdirection. The ring flange 32 has a surrounding axial step 38 so thatthe sealing element 28 does not project beyond the flange upper side 34in the axial direction despite the engagement around the edge. Thissimplifies the direct resting of the sealing bellows 20 against anexposed contact surface 40 provided on the flange upper side 34 (seeFIG. 3).

The sealing element 28 can also be manufactured separately from theretaining ring 26, wherein in this embodiment, the sealing element isprovided with a radial groove, similar to a pocket, into which theperipheral edge 54 is inserted.

FIG. 4 shows a further detail section through the sealing assembly 22according to the first embodiment, the sealing assembly 22 being alreadymounted to a ball joint 10. The sleeve-shaped portion 30 rests againstthe shank portion 16 of the ball stud 12, and the sealing element 28rests against an adjacent component 42. Furthermore, both thesleeve-shaped portion 30 and the ring flange 32 each form a contactsurface 40 against which the sealing bellows 20 directly rests in theassembled state of the ball joint 10.

FIG. 5 shows a section through the retaining ring 126 of the sealingassembly 122 according to a second embodiment. This second embodimentdiffers from the first embodiment according to FIGS. 2 to 4 only in thatrecesses 148, here through openings 44, are provided in the ring flange132.

In the radial direction, the recesses 148 are arranged approximately inthe region of the axial step (FIG. 5) and are uniformly distributed overthe periphery of the ring flange 132 (see top view in FIG. 6).

In this variant embodiment, the sealing element 128 is also preferablydirectly injection-molded with the retaining ring 126 so that thematerial of the sealing element 128 completely fills the recesses thusforming a projection 152, and contributes to a reinforcement of theinterlocking fit between the sealing element 128 and the retaining ring126 (FIG. 7). An interlocking fit is in particular realized by theserecesses 148, by means of which the retaining ring 126 and the sealingelement 128 are also fixed to each other free of play in the peripheraldirection.

FIGS. 8 and 9 each show a section through the sealing assembly 22according to a third and a fourth embodiment, respectively, theretaining ring 26 without the sealing element 28 being respectivelyrepresented on the left side, and the retaining ring 26 with the sealingelement 28 being respectively represented on the right side. In thethird embodiment, the ring flange 32 has recesses 48, preferably throughopenings 44, which have a chamfer adjacent to the flange upper side 34.The realized cone forms part of the flange upper side and ensures theinterlocking fit in one of the axial directions and in the radialdirections. The cone prevents a downward movement of the sealing element28 with respect to the ring flange 32 (see FIGS. 8 and 9) without thesealing element 28 engaging around the peripheral edge 54 of the ringflange 32.

In alternative variant embodiments, it is not necessary that the ringflange has through openings.

To form the interlocking fit, it is generally sufficient that the ringflange 32 is provided with at least one projection 46 and/or at leastone recess 48, the projection 46 of the ring flange 32 engaging in arecess 50 of the sealing element 28 (see FIG. 8), and a projection 52 ofthe sealing element 28 engaging in the recess 48 of the ring flange 32(FIG. 9), respectively.

This at least one projection 46, 52 and the at least one recess 48, 50are preferably configured so as to be complementary, so that theretaining ring 26 and the sealing element 28 are fixed to each otherfree of play in the axial and in the radial direction.

In the embodiments according to FIGS. 1 to 9, the ring flange 32respectively has a substantially disk-shaped peripheral edge 54 whichruns out freely outwards in the radial direction. In contrast thereto,FIGS. 10 a and 10 b show a fifth embodiment of the sealing assembly 22in which the ring flange 32 extends radially outwards and defines theouter peripheral edge 54, the ring flange 32 being bent inwards at theouter peripheral edge 54 so that at least parts of the ring flange 32are configured with two layers. In ring flanges 32 formed in this way,all faces facing the sealing bellows 20 in the assembled state of theball joint 10 are referred to as flange upper side 34, and all faces ofthe ring flange 32 facing away from the sealing bellows 20 are referredto as flange lower side 36. Here, the sealing element 28 extends up tobetween the two layers of the ring flange 32.

In this fifth embodiment, the ring flange 32 can optionally also beprovided with slots 56 (see FIGS. 10 a and 10 b, on the left) orrecesses 48 (see FIGS. 10 a and 10 b, on the right) to reinforce theinterlocking fit between the sealing element 28 and the retaining ring26.

FIG. 11 shows the sealing assembly 22 according to a sixth embodiment inwhich recesses 48 are formed in the ring flange 32 and projections 52are formed in the sealing element 28, the projections 52 filling therecesses 48 preferably completely. The projections 52 have a free upperend 58, the projections 52 preferably having a widened section towardstheir free end 58 (see FIG. 11, on the right). Therefore, due to thesecooperating projections 52 and recesses 48, an interlocking fit is againrealized by means of which the retaining ring 26 and the sealing element28 are fixed to each other free of play in the radial and in the axialdirection (i.e. more precisely in both axial directions).

FIG. 12 shows a seventh embodiment of the sealing assembly 22 in whichthe interlocking fit between the retaining ring 26 and the sealingelement 28 is realized by reshaping the ring flange 32. FIG. 13 showsthe initial shape of the retaining ring 26 before a reshaping of thering flange 32. The planar annular sealing element 28 according to FIG.14 is moved from the bottom to the retaining ring 26 according to FIG.13, the ring flange 32 being then reshaped, in particular edged so thatthe sealing assembly 22 according to FIG. 12 is produced.

FIG. 15 shows the sealing assembly 22 according to an eighth embodimentwhich is very similar to the seventh embodiment according to FIGS. 12 to14. The only difference is that the sealing element 28 according to FIG.17 has a different cross-sectional shape and therefore needs not bedeformed when it is guided to the retaining ring 26 (FIG. 16) or uponedging of the ring flange 32. Furthermore, the sealing element 22 inthis embodiment includes a resting surface 60 for the component 42 (seeFIG. 4) advantageously extending perpendicularly to the ring axis A.

FIGS. 18 to 21 show the sealing assembly 22 according to a ninthembodiment which is very similar to the first embodiment according toFIGS. 1 to 4. Analogously to the first embodiment, an exposed contactsurface 40 is provided on the flange upper side 34 facing the sealingbellows 20, so that the sealing bellows 20 rests directly against thering flange 32 of the retaining ring 26 in the assembled state (see FIG.20). Moreover, the sealing element 28 also rests against or engages thering flange 32, more precisely the flange upper side 34 thereof. Incontrast to the first embodiment, the sealing element 28 howeverprojects radially outside the contact surface 40, i.e. in the region ofthe engagement around the edge, in the axial direction beyond thecontact surface 40. For a protection and a sealing of the contact pointbetween the retaining ring 26 and the sealing bellows 20, the sealingelement 28 has a surrounding sealing lip 62 contacting a bellows mouth64 of the sealing bellows 20. The bellows mouth 64 has a bellows sealinglip 68, the sealing lip 62 resting against the bellows sealing lip 68,and its cross-sectional shape being adapted to a contour of the bellowssealing lip 68, preferably in that the opposed surfaces are configuredin a mirror-inverted manner.

On an end face directed radially inwards, the sealing lip 62 has aconcave contour. This concave contour of the sealing lip 62 and thecontour of the bellows sealing lip 68 preferably formed complementarilythereto form a self-reinforcing seal between the sealing lip 62 and thebellows sealing lip 68 as an external influence, for example a water jetof a pressure washer incident in this region, does not impair butimproves the sealing effect.

In a variant embodiment according to FIG. 21, a contact surface betweenthe sealing lip 62 and the bellows sealing lip 68 is formed as alabyrinth seal 70. This labyrinth seal 70 is produced by complementaryprojections and recesses in the sealing lip 62 and in the bellowssealing lip 68 which results in a toothing leading to a furtherimprovement of the sealing effect. The labyrinth seal 70 can be formedby a planar contact between the sealing lip 62 and the bellows sealinglip 68 or by a meander-shaped small slot between them.

Furthermore, the sealing element 28 of the sealing assembly 22 has asurrounding bead 66 for protecting the bellows mouth 64, the bead 66extending axially towards the sealing bellows 20 (see FIG. 20). Inparticular when using pressure washers, it has been found that the bead66 prevents a direct contact of splashed water with a bellows sealinglip 68 of the bellows mouth 64 by a deflection of the high pressure jet,the useful life of the bellows sealing lip 68 being thus increased.

Like in the embodiments shown above, the ring flange 32 of the retainingring 26 firmly held on the conical shank portion 16 is pressed against acontact surface of the component 42 upon assembling of the sealingassembly 22, the part of the elastic sealing element 28 mounted to theflange lower side 36 with an interlocking fit causing a sealing of thecontact point to the component 42 and therefore preventing a progressingcorrosion infiltration by penetrating moisture at the shank portion 16of the ball stud 12. To ensure a particularly reliable sealing withrespect to the component 42, the resting surface 60 of the sealingelement part mounted to the flange lower side 36 is preferablyconfigured in a profiled manner (see FIG. 18).

The realization of the sealing element 28 with the surrounding sealinglip 62 and/or the surrounding bead 66 for a protection between thecontact point between the retaining ring 26 and the sealing bellows 20is possible in all embodiments of the sealing assembly 22 in which thesealing element 28 adjoins the flange upper side 34.

In accordance with the provisions of the patent statutes, the principleand mode of operation of this invention have been explained andillustrated in its preferred embodiments. However, it must be understoodthat this invention may be practiced otherwise than as specificallyexplained and illustrated without departing from its spirit or scope.

What is claimed is:
 1. A sealing assembly of a ball joint for a vehiclecomprising: a retaining ring which includes a ring axis and a radialring flange having a flange upper side and an opposed flange lower side,and a sealing element which rests against the flange upper side andagainst the flange lower side and is connected to the retaining ringwith an interlocking fit, the interlocking fit being configured suchthat the retaining ring and the sealing element are fixed to each otherfree of play in the axial and in the radial direction, and the flangeupper side having an exposed contact surface for a sealing bellows,wherein the ring flange extends radially outwards and forms an outerperipheral edge, the ring flange being bent inwards at the outerperipheral edge so that at least parts of the ring flange are configuredwith two layers.
 2. The sealing assembly according to claim 1, whereinthe sealing element extends between the two layers of the ring flange.3. The sealing assembly according to claim 1, wherein about half of aradial dimension of the ring flange is configured with two layers. 4.The sealing assembly according to claim 1, wherein the sealing elementis a washer having a substantially constant axial dimension.
 5. Thesealing assembly according to claim 1, wherein the sealing element is awasher having a wedge-shaped cross section, an axial dimension of thewedge-shaped washer increasing radially outwards.
 6. The sealingassembly according to claim 5, wherein the wedge-shaped washer includesa projection extending radially outwards between the two layers of thering flange.
 7. The sealing assembly according to claim 1, wherein thesealing element includes a resting surface for a component of the balljoint, the resting surface extending perpendicular to the ring axis. 8.A sealing assembly of a ball joint for a vehicle comprising: a retainingring which includes a ring axis and a radial ring flange having a flangeupper side and an opposed flange lower side, and a sealing element whichrests against the flange upper side and against the flange lower sideand is connected to the retaining ring with an interlocking fit, theinterlocking fit being configured such that the retaining ring and thesealing element are fixed to each other free of play in the axial and inthe radial direction, and the flange upper side having an exposedcontact surface for a sealing bellows, wherein the ring flange extendsradially outwards and forms an outer peripheral edge, the ring flangebeing bent inwards at the outer peripheral edge so that at least partsof the ring flange are configured with two layers, wherein the sealingelement extends between the two layers of the ring flange, wherein thesealing element is a washer having a wedge-shaped cross section, anaxial dimension of the wedge-shaped washer increasing radially outwards.9. A sealing assembly of a ball joint for a vehicle comprising: aretaining ring which includes a ring axis and a radial ring flangehaving a flange upper side and an opposed flange lower side, and asealing element which rests against the flange upper side and againstthe flange lower side and is connected to the retaining ring with aninterlocking fit, the interlocking fit being configured such that theretaining ring and the sealing element are fixed to each other free ofplay in the axial and in the radial direction, and the flange upper sidehaving an exposed contact surface for a sealing bellows, wherein thering flange extends radially outwards and forms an outer peripheraledge, the ring flange being bent inwards at the outer peripheral edge sothat at least parts of the ring flange are configured with two layers,wherein the sealing element extends between the two layers of the ringflange, wherein the sealing element includes a resting surface for acomponent of the ball joint, the resting surface extending perpendicularto the ring axis.